Re: Allow underscore in non-binding clauses of `if-let*` and friends

[Jens Schmidt <jschmidt4gnu@vodafonemail.de>]

On 2024-11-12  14:36, Joost Kremers wrote:

> We already use underscore to mean "ignore this variable" in several
> contexts, so this seems consistent. It also macro-expands to the same
> code as the one without underscore, so it's not less efficient.

Actually, in a recent master your snippet even expands to

  (let*
      ((s (and t (foo (some-computation))))
       (s (and s (bar (some-other-computation))))
       (baz (and s (y-or-n-p "Hi? "))))
    (if baz (message "yes")))

with (uninterned) symbols s being used in place of `_'.

Seems that Michael has already seen to that:

  commit e680827e814e155cf79175d87ff7c6ee3a08b69a
  Author: Michael Heerdegen <michael_heerdegen@web.de>
  Date:   Fri Feb 16 22:07:18 2024 +0100

    Don't warn about _ not left unused in if-let and alike
    
    The macro expansions did not leave a variable _ unused; this triggered
    an irritating compiler warning (bug#69108).
    
    * lisp/subr.el (internal--build-binding): Handle bindings of the form
    (_ EXPR) separately.

And I might consider using underscores instead of alignment ...